Heretofore stereo rendition was only possible by utilizing at the source or point of pickup at least two microphones suitably displaced from each other. Similarly, two loudspeakers were required at point of reception. Interconnecting transmission requires dual audio channels and audio modulated multiplex circuitry for radio transmission.
Meaningful stereo reception tacitly assumes equal hearing sensitivity in both ears of the listener or the addition of loudness controls to accomplish it. Identical sound patterns are emitted by two loudspeaker which are laterally displaced to realize a stereo effect on a listener's ears within an intervening area. The relative position of the loudspeakers to each other and to the listener, as well as the acoustic properties of the surrounding, determine the ultimate stereo quality as perceived by the listener.